线程对象在不同时期有不同的状态，该状态信息存在于Thread.State这个枚举类中
1 public enum State { 2 /** 3 * Thread state for a thread which has not yet started. 4 */ 5 NEW, 6 7 /** 8 * Thread state for a runnable thread. A thread in the runnable 9 * state is executing in the Java virtual machine but it may 10 * be waiting for other resources from the operating system 11 * such as processor. 12 */ 13 RUNNABLE, 14 15 /** 16 * Thread state for a thread blocked waiting for a monitor lock. 17 * A thread in the blocked state is waiting for a monitor lock 18 * to enter a synchronized block/method or 19 * reenter a synchronized block/method after calling 20 * {@link Object#wait() Object.wait}. 21 */ 22 BLOCKED, 23 24 /** 25 * Thread state for a waiting thread. 26 * A thread is in the waiting state due to calling one of the 27 * following methods: 28 * <ul> 29 * <li>{@link Object#wait() Object.wait} with no timeout</li> 30 * <li>{@link #join() Thread.join} with no timeout</li> 31 * <li>{@link LockSupport#park() LockSupport.park}</li> 32 * </ul> 33 * 34 * <p>A thread in the waiting state is waiting for another thread to 35 * perform a particular action. 36 * 37 * For example, a thread that has called <tt>Object.wait()</tt> 38 * on an object is waiting for another thread to call 39 * <tt>Object.notify()</tt> or <tt>Object.notifyAll()</tt> on 40 * that object. A thread that has called <tt>Thread.join()</tt> 41 * is waiting for a specified thread to terminate. 42 */ 43 WAITING, 44 45 /** 46 * Thread state for a waiting thread with a specified waiting time. 47 * A thread is in the timed waiting state due to calling one of 48 * the following methods with a specified positive waiting time: 49 * <ul> 50 * <li>{@link #sleep Thread.sleep}</li> 51 * <li>{@link Object#wait(long) Object.wait} with timeout</li> 52 * <li>{@link #join(long) Thread.join} with timeout</li> 53 * <li>{@link LockSupport#parkNanos LockSupport.parkNanos}</li> 54 * <li>{@link LockSupport#parkUntil LockSupport.parkUntil}</li> 55 * </ul> 56 */ 57 TIMED_WAITING, 58 59 /** 60 * Thread state for a terminated thread. 61 * The thread has completed execution. 62 */ 63 TERMINATED; 64 }
截图自JDK1.8的API
截自《Java多线程编程核心技术》
